e p i l o g - Fakultät für Informatik, TU Wien

Thomas Strnad
Validation of the DECOS Encapsulated Execution Environment
Studium: Diplomstudium Informatik
BetreuerIn: O.Univ.Prof. Dr. Hermann Kopetz
Abstrakt: The DECOS (Dependable Embedded COmponents and Systems)
integrated architecture allows the integration of different embedded
application sub-systems with different criticality into the same hardware
infrastructure. In the DECOS integrated architecture, computational
resources (CPU time, memory, I/O) and communication resources (network
bandwidth) are shared among multiple software components in order to
reduce the number of deployed embedded computer nodes, which implies
the reduction of system cost. The DECOS integrated architecture consists of
four layers: the I/O layer, the application layer, the middleware layer, and
the core layer. Distributed soft- ware applications run at the application
layer. So called DECOS high-level services (virtual network service, virtual
gateway service, diagnostic service) are executed in the middleware layer.
The core layer provides services that are in charge of predictable and faulttolerant
communication among different DECOS integrated nodes. In order
to perform a seamless integration of different software modules that may
be developed by different vendors, the DECOS integrated architecture
services guarantee that different applications do not affect the operation of
each other in an undesired manner: An application job that is executed in
one of the DECOS components can not affect other application jobs or
DECOS services. A prototype implementation of the DECOS integrated
architecture was developed at the Vienna University of Technology. The
encapsulated execution environment is in charge of preventing non- specified
interaction among the application jobs (implemented as LXRT tasks)
executed in the DECOS components. The encapsulated execution
environment is implemented by using the Linux operating system with RTAI
and LXRT patches. The objective of this work is to validate whether Linux-
RTAI-LXRT fulfils the requirements to be used as an encapsulated execution
environment in the DECOS integrated architecture. Validation is performed
by means of software implemented fault injection (SWIFI). SWIFI is usually
deployed to emulate the occurrence of hardware faults. In this work, SWIFI
is used to perform the emulation of software faults in order to observe, if a
faulty application job that is executed in a DECOS component can affect the
operation of other application jobs or the DECOS services.
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